Possible public health hazards have impeded the recycling of sewage sludge as a fertilizer or soil amendent and as an additive to livestock feed. It is desirable to recycle sewage sludge to such beneficial uses because other means of sludge disposal have become increasingly expensive monetarily as well as in terms of energy and ecology.
Pumping liquid sewage or sewage sludge through a radiation chamber to kill or inactivate pathogens may be uncompetitive with conventional sludge treatment because the relatively expensive radiation source is being used in an inefficient manner, irradiating water rather than pathogens. Using a conventional conveyor in the irradiation of dry sewage sludge also leads to size objections and a wasting of radiation as rays could escape through open areas between containers or buckets.